Pork would, at least in the ancient era, give you trichinosis easily... which you *don't* want.
Most of the food taboos end up health matters if you look hard enough into them. Shellfish back then would have been teeming with bacteria from the open sewage dumping, milk wasn't pasteurized so had natural bacteria and wasn't a good idea to mix with beef in a dish, even the requirement to clean the kitchen with boiling water can be seen as a old health matter.
Nowadays the swine are tested, the shellfish is deep-sea and cleaner, the milk is darn near sterile, and the kitchen surfaces don't absorb anything. Where's my ham sandwich with shrimp and beef stroganoff!
[coughcoughbullsh*tcoughcough]
In Judaism (and I assume Islam as well) the only prohibition is on eating pork.
Please correct me if I am wrong, Rabbi, but doesn't Judaism forbid seafood if it does not have scales and fins? Thereby precluding shellfish from the diet?
I just read about the "milk and meat in the same dish" portion too. Is this also incorrect?
I just found this. Are all of these incorrect?
"The Details
Animals that may not be eaten
Of the "beasts of the earth" (which basically refers to land mammals with the exception of swarming rodents), you may eat any animal that has cloven hooves and chews its cud. Lev. 11:3; Deut. 14:6. Any land mammal that does not have both of these qualities is forbidden. The Torah specifies that the camel, the rock badger, the hare and the pig are not kosher because each lacks one of these two qualifications. Sheep, cattle, goats and deer are kosher.
Of the things that are in the waters, you may eat anything that has fins and scales. Lev. 11:9; Deut. 14:9. Thus, shellfish such as lobsters, oysters, shrimp, clams and crabs are all forbidden. Fish like tuna, carp, salmon and herring are all permitted.
For birds, the criteria is less clear. The Torah lists forbidden birds (Lev. 11:13-19; Deut. 14:11-18), but does not specify why these particular birds are forbidden. All of the birds on the list are birds of prey or scavengers, thus the rabbis inferred that this was the basis for the distinction. Other birds are permitted, such as chicken, geese, ducks and turkeys.
Of the "winged swarming things" (winged insects), a few are specifically permitted (Lev. 11:22), but the Sages are no longer certain which ones they are, so all have been forbidden.
Rodents, reptiles, amphibians, and insects (except as mentioned above) are all forbidden. Lev. 11:29-30, 42-43.
As mentioned above, any product derived from these forbidden animals, such as their milk, eggs, fat, or organs, also cannot be eaten. Rennet, an enzyme used to harden cheese, is often obtained from non-kosher animals, thus kosher hard cheese can be difficult to find."
from
http://www.jewishvirtuallibrary.org/jsource/Judaism/kashrut.html
